Transcatheter atrio-ventricular valve prosthesis

ABSTRACT

A transcatheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular valve in a connection channel, having a circumferential connection channel wall structure, between atrial and ventricular chambers of a heart, including an inner device to be disposed in the interior of the connection channel, the inner device having a circumferential support structure which is radially expandable and having a valve attached to the circumferential support structure, and an outer device to be disposed on the exterior of the connection channel, wherein the outer device at least partly extends around the inner device at a radial distance to the inner device, wherein the inner and outer devices form a securing mechanism for securing the circumferential connection channel wall structure therebetween.

This application is a continuation application of U.S. patentapplication Ser. No. 15/884,953, filed Jan. 31, 2018, which in turn is acontinuation application of U.S. patent application Ser. No. 15/153,333,filed May 12, 2016, which in turn is a divisional application of U.S.patent application Ser. No. 13/808,838, filed Jan. 7, 2013, which is aNational Stage of PCT/IB2011/002282, filed Jun. 30, 2011. The presentapplication claims priority and benefit of U.S. provisional applicationNo. 61/363,070 and of German patent application No. 10 2010 036 824.5.The entire content of the prior applications is incorporated herein byreference.

FIELD OF INVENTION

The invention relates to atrio-ventricular valve (mitral valve ortricuspid valve) replacement devices for functionally replacing thecorresponding native atrio-ventricular valve, and, in more detail, to atranscatheter atrio-ventricular valve replacement device ortranscatheter atrio-ventricular valve prosthesis which allowsimplantation by means of a percutaneous approach, that is, a minimallyinvasive approach on a beating heart.

MEDICAL BACKGROUND

Normally the mitral valve allows blood to flow freely from the leftatrial chamber to the left ventricular chamber during diastole when theheart is relaxed and prevents the backflow of blood from the leftventricle to the left atrium during systole when the heart contracts.The mitral valve or mitral valve structure has a generallycircumferential wall structure forming a connection channel or throughopening between the atrial and ventricular chambers of the heart andincluding a circumferential valve annulus, valve leaflets opening andclosing the connection channel/through opening at a position close tothe valve annulus, a generally circumferential chord structure (chordaetendinae) connected between the valve leaflets and generallycircumferential papillary muscle(s), and said circumferential papillarymuscle(s).

Proper opening and closing of the mitral valve leaflets depends on thecoordinated function of its individual components i.e., the mitralannulus, the anterior and posterior mitral valve leaflets, chordaetendineae, papillary muscles, and the left atrial and left ventricular(LV) walls in continuity with the leaflets, and papillary muscles,respectively.

Mitral valve disease can take the form of mitral stenosis or mitralregurgitation. Mitral stenosis results when the valve does not openfully during diastole. In this case, higher than normal pressures arerequired to push blood forward into the left ventricle. Mitralregurgitation (MR) is a condition whereby the mitral valve does notclose properly when the left ventricle contracts during left ventricularcontraction. As a result, there is abnormal leaking of blood from theleft ventricle into the left atrium.

Mitral pathology may basically be treated by valve repair or valvereplacement. The treatment of mitral steno sis was revolutionized in1984 and 1985 when Inoue and Lock developed percutaneous mitral balloonvalvotomy. Echocardiography is essential for patient screening andpredicting the likelihood of a successful percutaneous balloon mitralvalvotomy (PBMV). Nevertheless, predicting the outcome of percutaneousmitral balloon valvotomy remains somewhat limited. In cases where themitral valve leaflets are severely restricted, thickened, and/orcalcified and the submitral apparatus is severely thickened and/orcalcified, surgical mitral valve replacement or repair needs to beconsidered. Mitral valve surgery is also indicated in patients withconcomitant moderate to severe mitral regurgitation or left atrialthrombus. Although there is some data comparing the outcomes of PBMV tosurgical commissurotomy for patients with mitral stenosis, there is apaucity of data comparing the outcomes of PBMV to surgical mitral valvereplacement. The outcomes of PBMV were just as good or better thansurgical commissurotomy in patients who were candidates for PBMV.

Mitral regurgitation can result from an abnormality of the mitral valveleaflets or chordae tendinae, in which case it is called primary ordegenerative mitral valve disease. On the other hand, mitralregurgitation can occur in the setting of normal mitral valve leafletsand chordae tendinae; known as secondary or functional mitralregurgitation. In this case, a dilated left ventricle from ischemic ornon-ischemic origin can result in mitral annular dilatation or a changein position of the papillary muscles and lead to abnormal closing of themitral valve leaflets.

Mitral regurgitation is an important health problem. It affectsapproximately 9% of the population above 75 years old. Of the 5 millionpatients suffering from heart failure in the United States, 15-20% arefound to have moderate to severe mitral regurgitation. The occurrence ofmitral regurgitation early after a myocardial infarction (MI) isreported to be 50% (mild in 38%, moderate-severe in 12%). Short- andlong-term survival is worse when mitral regurgitation of any severityaccompanies heart failure or a myocardial infarction.

Although surgical mitral valve repair or replacement remains thestandard of care for patients with significant mitral valve disease, theEuropean Heart Survey demonstrated that up to one-half of patients withsevere symptomatic mitral regurgitation do not undergo surgery. Comparedwith those who underwent surgery, these patients were typically older,had impairment of left ventricular function, and had more noncardiacdiseases than did patients undergoing valve surgery. Whether denyingsurgery in these patients was justified or not, the challenges ofmanaging these patients will only increase in the coming years as thenumber of patients considered for surgery continues to rise.

Although surgical mitral valve repair and replacement can be associatedwith an acceptable mortality risk approaching 1% and 6%, respectively,it requires a sternotomy and cardiopulmonary bypass that can beassociated with significant complications. More specifically, theoccurrence of any major complication (e.g. operative mortality,myocardial infarction, tamponade, septicemia, stroke, re-operation,renal failure, deep wound infection, ventilatory support >24 hours andGI bleed) can be as high as 12% and 25% for mitral valve repair andreplacement, respectively (STS database 2002).

Previous data published from the mid 1990's suggested that surgicalmitral valve repair had better short- and long-term survival chancesthan mitral valve replacement (Circulation 1995; 91:1022). It isimportant to note that the Starr Edwards valve was the most frequentlyutilized mechanical valve in that study. Since then, there has been abetter understanding of the techniques for surgical mitral valvereplacement. For instance, preservation of the chords and maintainingthe submitral apparatus intact during mitral valve replacement has beenassociated with improved indices of left ventricular end systolicfunction (Circulation 1992; 86:1718-1726). In addition, the use ofbioprosthetic over mechanical mitral valves has been shown to reduce theincidence of valve-related complications such as bleeding (JACC 200;36:1152-1158). In a propensity-matched analysis, the probability ofre-operation was higher after mitral valve repair than mitral valvereplacement.

Mitral valve annuloplasty is the cornerstone of mitral valve repair.Annuloplasty may be used together with leaflet repair (resection,sliding annuloplasty) or chordal reconstruction (transposition,artificial chords). For repair of a degenerative mitral valve, failureto include an annuloplasty procedure negatively affects the long-termresults of the procedure.

The Alfieri procedure involves suturing the free edges of the middleanterior and middle posterior leaflets of the mitral valve. Thisproduces a double orifice mitral valve. The procedure can be used totreat degenerative or functional mitral regurgitation Like leafletrepair, the Alfieri procedure requires concomitant annuloplasty to avoidrepair failure.

The clinical benefits and durability of mitral valve repair in thesetting of severe functional mitral regurgitation are controversial;especially in the setting of severe left ventricular dilatation anddysfunction (JACC 2008; 52:319-26) (JACC 2005; 45:381-7) (Circulation1998; 98:Suppl II:124-7) (Sem Cardiovasc Surg 2002; 14:133-6).Furthermore, the respective role of mitral valve repair and replacementin this setting is also unclear. Although mitral valve replacement withchordal preservation is associated with a higher operative mortalitythan mitral valve repair, replacement offers a significantly lowerfailure rate. The failure rate of mitral valve repair for secondarymitral regurgitation can be as high as 30% at 1-2 years follow-up. Mostof the literature pertaining to secondary mitral regurgitation andsurgical therapy is based on mitral valve repair rather than mitralvalve replacement. It can be hypothesized that the lack of mortalitybenefit associated with mitral valve repair is in some ways related tothe poor durability results with mitral valve repair than mitral valvereplacement.

In an effort to address the challenges ahead, researchers have beendeveloping new options for a rapidly growing pool of patients in whomheart valve replacement or repair may be beneficial, but for whomsurgical intervention is considered too high risk.

The goal of transcatheter valve therapy is to provide a treatmentmodality that is less invasive, associated with equal or greaterefficacy compared with standard surgery, and is potentially safercompared to more invasive procedures.

To overcome limitations of surgical mitral valve implantation, severaltechniques have been proposed for minimally invasive or endovascularvalve implantation in the mitral and/or tricuspid position.

Most catheter delivered devices are based on stents to enablecollapsation and re-expansion, anchoring and sealing contact with theanatomy. Stents, whether balloon- or self-expandable, anchor by innerradial force on the anatomy. However the atrio-ventricular heart valvesdo not offer a substantially cylindrical location like a vessel or anaortic or pulmonary valve. Consequently anchoring by inner radial forceis unstable. Furthermore, the valve annulus usually is very supple andextends significantly under inner radial force which can be deleteriousto the anchoring and to the heart function. In addition the size andshape of the mitral valve annulus varies considerably in diseasedvalves. Therefore many different diameters for prosthetic replacementdevices would be necessary.

Several authors have described alternative ways to anchor a valveprosthesis in the atrio-ventricular position. Some rely on a specificshape enabling a firm anchoring without the need of inner radial forcelike Hill et al. (US20100036479) describing a cage like constructionfilling the atrium and enabling to rest on the atrial wall over itscomplete surface. However, this technique will considerably impairatrial function, because atrial contraction is impeded. Quadri et al.(US2009306768) and Lamphere et al. (US20080221672) suggested the use ofhooks engaging the valve annulus. Rowe et al. (US20090276040) describedboth a specific shape and a tether that can be anchored in theventricular wall to resist dislodgment. Likewise Lutter (DE102007043830A1) et al. describe a prosthesis which is anchored by broad extensionsin the left atrium and held in place by countertraction through fixationin the left ventricular apex. In contrast Thambar et al. (US20080243245)describe a prosthesis which is anchored on the ventricular side of themitral valve and held in place by countertraction through the leftatrial wall. Both Palmaz et al. (WO03003943) and Leonhardt et al. (U.S.Pat. No. 5,957,949) suggest a prosthesis which is fixed in the mitralvalve annulus by radial force, supported by some longitudinalcompression through atrial and ventricular extensions. A differentapproach is presented by Laske et al. (WO 2008091515) who describe a twodouble barrel stent design, fixed in the mitral annulus by radial force.

While those authors describe means to achieve anchoring of a collapsiblevalve device, there is no clear description on how they achieve sealingcontact to avoid per-prosthetic leakages. Furthermore there is nomention on how the prosthesis can accommodate different ring sizes andshapes.

Furthermore, to avoid pushing the anterior mitral leaflet in the outflowtract and obstructing the blood flow out of the ventricle, such authorsdescribe specific requirements. Quadri's device is anchored on theannulus and it does not reach inside the ventricle between the mitralleaflets but rather protrudes proximally inside the left atrium creatinga no-flow zone and the risk of thrombus. Part of the free floatinganterior leaflet which is not fixed by the hooks on the ventricular sideof the stent may even protrude into the left ventricular outflow tractcausing SAM. Rowe's device requires a distal end smaller than theproximal end.

All of the devices described above share the same potentially unresolvedissues.

-   -   1. The mitral valve ring may give way to inner radial forces.    -   2. The variations in ring shape and size may not be fitted for        all prostheses.    -   3. There could be mitral paravalvular regurgitation because the        zone between the valve stent and the leaflet may not be sealed.    -   4. An anchoring through the apex restricts the prosthesis to the        use by surgeons and may compress the left ventricle in its        cranial-caudal dimension.

SUMMARY OF THE INVENTION

Embodiments of a transcatheter atrio-ventricular valve prosthesis forfunctional replacement of an atrio-ventricular valve in a connectionchannel, having a circumferential connection channel wall structure,between atrial and ventricular chambers of a heart, comprise an innerdevice to be disposed in the interior of the connection channel, theinner device having a circumferential support structure which isradially expandable and having a valve attached to the circumferentialsupport structure, and an outer device to be disposed on the exterior ofthe connection channel, wherein the outer device at least partly extendsaround the inner device in a radial distance to the inner device,wherein the inner and outer devices form a clamping mechanism forclamping the circumferential connection channel wall structuretherebetween. Further embodiments of the invention provide methods forimplanting a transcatheter atrio-ventricular valve prosthesis.

Exemplary techniques and apparatuses, including prostheses, forpracticing embodiments of the invention are shown in the attachedfigures and the descriptive appearing thereon. The features describedherein can be used in various combinations, which are intended to beencompassed hereby. The disclosure of the embodiments as disclosedherein is not intended to restrict the invention to those specificembodiments, but to encompass all embodiments of the concepts addressedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to an embodiment of theinvention.

FIGS. 2A-2E show steps of an implantation approach for implantation theprosthesis according to an embodiment of the invention.

FIG. 3 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIGS. 4 and 5 show other implantation approaches for implantation theprosthesis according to an embodiment the invention.

FIG. 6 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 7 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 8 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 9 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 10 shows a schematic perspective view of a further approach forimplanting a transcatheter atrio-ventricular valve according to anembodiment of the invention.

FIG. 11A shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 11B shows a section along line B-B in FIG. 11A.

FIGS. 12A-12J show sectional views for explaining an approach forimplanting the outer device of the prosthesis according to an embodimentof the invention.

FIGS. 13A and 13B show a sectional perspective side view and a sectionalperspective top view of a transcatheter atrio-ventricular valveprosthesis according to another embodiment of the invention.

FIGS. 14A and 14B show sectional views for explaining an approach forimplanting the prosthesis according to the embodiment of FIGS. 13A and13B.

FIG. 15 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to another embodiment ofthe invention.

FIG. 16 shows a schematic perspective view of a transcatheteratrio-ventricular valve prosthesis according to an exemplary embodiment.

In the figures, the same reference signs are used to identify same andsimilar parts and elements.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Implantation of a transcatheter atrio-ventricular valve prosthesis(mitral valve or tricuspid valve prosthesis) on a beating heart can beachieved by a minimally invasive approach in a mammal. Thisspecification describes procedures and apparatuses, including the valveprosthesis itself, to insert and deploy the valve prosthesis and toanchor it by attachment to locations inside the heart.

According to an embodiment, the invention provides a transcatheteratrio-ventricular valve prosthesis. According to another embodiment, theinvention provides a method for implanting a transcatheteratrio-ventricular valve prosthesis. Further embodiments of the inventionare described below.

According to an embodiment of the invention, a transcatheteratrio-ventricular valve prosthesis for functional replacement of anatrio-ventricular valve in a connection channel, having acircumferential connection channel wall structure, between atrial andventricular chambers of a heart is provided, comprising an inner deviceto be disposed in the interior of the connection channel, the innerdevice having a circumferential support structure or circumferentialsupport body which is radially expandable and having a valve attached tothe circumferential support structure, and an outer device to bedisposed on the exterior side of the connection channel, wherein theouter device at least partly extends around (circumferentially around)the inner device in a radial distance to the inner device, wherein theinner device, for example the circumferential support structure of theinner device, and the outer device form a clamping mechanism forclamping the circumferential connection channel wall structure of theconnection channel therebetween.

The circumferential support structure defines an inner channel or innerthrough opening forming a replacement channel for functionally replacingor re-enforcing the (native) connection channel between the atrialchamber and the ventricular chamber. In the implanted condition, thecircumferential support structure, for example, circumferentially andcontinuously abuts the inner periphery of the circumferential connectionchannel wall structure. The (new) valve is fixedly arranged in theinterior of the circumferential support structure and, thus, within saidreplacement channel, and is fixedly attached to the circumferentialsupport structure so as to be able to take over and correspondinglyreplace the function of the native valve, that is, so as to be able toappropriately open and close the replacement channel to appropriatelyallow blood flow therethrough between the atrial chamber and theventricular chamber, between which it is (or is to be) implanted.

According to another embodiment of the invention, a transcatheteratrio-ventricular valve prosthesis for functional replacement of anatrio-ventricular valve in a connection channel, having acircumferential connection channel wall structure, between the atrialchamber and the ventricular chamber of a heart is provided, comprisingan inner device to be disposed in the interior of the connectionchannel, the inner device having a circumferential support structurewhich is radially expandable, and having a valve attached to thecircumferential support structure, wherein the circumferential supportstructure of the inner device is of tubular shape and extends along anaxis and has two axial ends, and an outer device to be disposed on theexterior of the connection channel, wherein the outer device at leastpartly extends around the inner device in a radial distance to the innerdevice, and wherein the inner and outer devices form a clampingmechanism for clamping the circumferential connection channel wallstructure therebetween, wherein the outer device comprises a ring, forextending circumferentially around the circumferential connectionchannel wall structure, arranged between and in a distance to the axialends of the inner device, wherein the outer device further comprises ananchor member having one or more anchor parts, such as one or more barbsand/or one or more hooks, to penetrate into the circumferentialconnection channel wall structure at a position at or close to the ring,the anchor member comprising an eye, through which the ring extends tothereby be anchored on the circumferential connection channel wallstructure at this position by the anchor member.

The (native) connection channel between the native arterial andventricular chambers (which may be the left chambers in case of(functional) mitral valve replacement or right chambers in case of(functional) tricuspid valve replacement) is defined by thecircumferential and/or peripheral connection channel wall structureprovided by (the tissue of) the native valve leaflets, the native valveannulus of the native atrial-ventricular valve and, in an embodiment,may also be the adjacent muscular tissue, the generally circumferentialchord structure (chordae tendinae) between the valve leaflets and thegenerally circumferential papillary muscle(s), and said papillarymuscle(s), wherein the inner and outer devices are provided such as to(at least partly) circumferentially clamp said connection channel wallstructure therebetween. In the area of the native valve leaflets and thenative valve annulus, the circumferential connection channel wallstructure forms a substantially closed circumferential connectionchannel wall, and in the area of the chordae tendinae thecircumferential connection channel wall structure forms a longitudinallyslotted and, hence, more radially opened circumferential wall structure.The inner device is, for example, to be arranged within thecircumferential connection channel wall (formed by the valve annulus andthe leaflets), thereby achieving an improved sealing and fixationfunction. Also the outer device is, for example, to be arranged aroundthe mentioned circumferential connection channel wall (formed by thevalve annulus and the valve leaflets), and/or the outer device may alsobe arranged around the circumferential connection channel wall structurein the area of the chordae tendinae and/or in the area of the papillarymuscle(s) in as far as the inner device extends into between these/thisarea(s). According to a further extended approach, part of therespective atrium, for example that part of the respective atrium whichis adjacent to the corresponding atrio-ventricular valve to befunctionally replaced, may be considered to also form part of thecorresponding connection channel so that according to this extendedapproach the (native) circumferential connection channel wall structurewhich is to be clamped between the outer and inner devices is formed bya part of the corresponding atrium wall. In this respect, the outerdevice may also be arranged around the corresponding atrium.

The transcatheter atrio-ventricular valve prosthesis is preferablycollapsible to fit inside a delivery catheter and re-expandable to befunctional inside the heart cavity. In this respect, the circumferentialsupport structure of the inner device can be brought in a collapsedcondition to be then implanted in percutaneous manner, and can then beexpanded when being in its final implanted position within the (native)connection channel. The circumferential support structure can be astent-like component, and can be, for example, self expandable orballoon expandable. It can be made of nitinol or stainless steel or anymaterial enabling properties desired for the application (e.g.,biocompatibility, elasticity, yield strength, fatigue resistance,corrosion resistance). It can be laser-cut or assembled from a wire, orproduced by other methods. For example, the circumferential supportstructure can be formed by a mesh-like wire structure of either ashape-memory material, such as nitinol, thereby forming aself-expandable mesh structure, or of a non-shape-memory material, suchas stainless steel, thereby forming a non-self-expandable mesh structurewhich has to be expanded by an additional or separate expanding means,such as by an internal and expandable balloon which is inserted into aninterior of the initially collapsed circumferential support structureand which can be inflated and deflated to expand the circumferentialsupport structure and to be then removed therefrom, respectively.

Further, the circumferential support structure is, for example, of atubular shape (for example, of a tubular mesh shape) which iscollapsible and re-expandable to its tubular shape.

The expandability and corresponding collapsibility of thecircumferential support structure (the valve attached thereto iscorrespondingly collapsible and deployable) allows delivery of the innerdevice by means of a catheter forwarded to the atrio-ventricular valve,for example, via the corresponding atrial chamber or ventricularchamber.

The outer device can also be forwarded by means of a catheter to theatrio-ventricular valve, for example via the atrial chamber or theventricular chamber, wherein the inner and outer devices may beforwarded simultaneously or one after another via a respective (other)one of the atrial and ventricular chambers or via the respective same ofthe atrial and ventricular chambers.

The (new, replacing or non-native) valve attached to the circumferentialsupport member can be made of biological tissue, for example, ofpericardium, or it can be an artificial valve made of a syntheticmaterial, such as of a plastic film material, for example a PE filmmaterial. The non-native valve may be provided as a flap valve arrangedin an interior of the circumferential support structure of the innerdevice, and having one or a plurality of (co-acting) flaps.

When the circumferential support structure is in its finally implantedposition, for example between the native valve leaflets and/or thenative valve annulus, and will be expanded, the circumferential supportstructure radially and inwardly contacts against the inner periphery ofthe circumferential or peripheral connection channel wall structure, forexample against the inner periphery of the connection channel wallformed by the native valve annulus and the native valve leaflets. Inthis respect, the circumferential support structure may be expandable tomerely (in general) abut against the inner periphery without causinginner pressure as such. In this case, the active clamping action can becaused by an outer device which is a contractible device and which thencan radially and inwardly contract the circumferential connectionchannel wall structure against the inner device. It is also possiblethat the outer device is generally not radially contractible, and theclamping force can be actively provided by the inner device, that is, bythe expandable circumferential support structure radially expanded topress the (native) circumferential connection channel wall structureagainst the inner periphery of the outer device. It is also possiblethat both the inner device, for example its circumferential supportstructure, and the outer device are expandable and contractible,respectively, such that both provide for such radial forces so as to beable to actively press against the circumferential connection channelwall structure from the inner side and the outer side thereof.

The outer device may be one or more collapsible and correspondingly(re-)expandable or formable, for example circumferentially closed, ringsor tubular members, for example in form of one or a plurality of snares,which extend around, for example completely around, the (circumferenceof the) inner device and can be arranged around, for example completelyaround, the native connection channel and, hence, the outercircumference of the corresponding circumferential connection channelwall structure. Accordingly, by using a ring, the clamping mechanism cancontinuously (that is, without interruptions) circumferentially clampthe connection channel wall structure. The outer device may be a closedring (as shown in e.g., FIGS. 1 and 15) or circumferentially closedtubular member or may be formed as a clamp, for example, as acircumferentially open ring or tubular member (that is, a ring that isopen at its circumference such as, for example, a C-shaped ring or aU-shaped ring, or a helix, or a tubular member that is open at itscircumference along its longitudinal direction, such as a tubular memberhaving a C-shaped or U-shaped cross-section). Further in this respect,circumferentially open ring or tubular member means that thecorresponding (circumferential) free ends of the open ring or tubularmember are not connected to each other (are not interconnected) and,hence, are provided connection-free or locking-free. An example of anopen helical outer device is shown in FIG. 16. The outer device needs tobe deformable, for example collapsible, to also allow delivery thereofby means of a catheter in a percutaneous manner. In the event of anouter device shaped as a tubular member, whether eventually closed oropen, it can be made of a material inflatable through a lumen in thedelivery catheter, especially in order to take a certain shape or size.It can further be inflated with a material that can be injected in aliquid state and that can be turned into a solid, non deformablecomponent. This can be achieved for instance with a polymer hardeningover time or by further addition of energy (for example, heating,ultrasound, UV light or other electromagnetic radiation) or a hardening,drying or reticulating agent. Alternatively, or in addition, the outerdevice can be made tubular in order to be delivered while positionedover the delivery catheter rather than inside the delivery catheter'slumen. This could then enable delivery of a fastening mechanism (clip,screw, suture . . . ) from the inside of the delivery catheter to theinner side of the tubular outer device. This fastening mechanism couldperforate the tubular outer device so as to enable attachment of one endof the outer device to the other end or of an area of the outer deviceto the anatomy (connection channel wall structure) or to the innerdevice.

A wire, which may also be a ribbon or a rope, may be used as materialfor the outer device, the wire forming the above-mentioned ring aroundthe circumferential connection channel wall structure. The wire or wirematerial may be flexible and non-elastic, but may also be flexible andelastic so as to be able to always provide an elastic clamping forceagainst the inner device.

In general, the outer device may be non-elastically contractible up toany appropriate inner diameter, or the outer device may be elasticallycontractible up to an inner diameter which, for example is equal orsmaller than the outer diameter of the inner device, so as to ensure anelastic clamping force against the circumferential connection channelwall structure when being implanted.

The wire or wire material as such may be linearly forwarded to theatrio-ventricular valve through a catheter and may be woundcircumferentially around the outer periphery of the circumferentialconnectional channel wall structure to form the outer device in theshape of one or more rings such as snare rings. Such rings may bearranged in a respective distance to each other along an axial extensionof the inner device along the direction of the connectionchannel/through opening formed by native atrio-ventricular valve. Thewire ring can be easily further contracted to correspondingly contractthe connection channel and circumferential connection channel wallstructure radially inwardly against the inner device and thecircumferential support structure thereof. Thereby, a tight and therebysealed and reliable circumferential connection between thecircumferential support structure with the (new/replacing) valveattached thereto and the inner periphery/circumference of thecircumferential connection channel wall structure can be achieved. Inthis respect, as mentioned above, the inner device with itscircumferential support structure may be arranged within the nativevalve annulus or at an interior position close thereto and in-betweenthe native valve leaflets, and the outer device may be arranged aroundthe exterior of the native valve leaflets close to the native valveannulus to thereby circumferentially and tightly clamp the native valveleaflets, which form part of the connection channel and, thus, of theconnection channel wall structure thereof, between the inner and outerdevices, thereby providing for safe and reliable seal as well asfixation functions. As mentioned above, the inner device and/or theouter device may also and/or additionally be provided on the inner andouter, respectively, peripheries of further elements of thecircumferential connection channel wall structure, such as within andaround, respectively, the periphery of the chordae tendinae, theperiphery of the papillary muscle(s), and the periphery of the atrialwall.

The outer device, for example the ring, such as the wire ring or ribbonring, may be of a shape-memory material (e.g., Nitinol) so as to be ableto create a contracting force around the native leaflet and innerdevice, without requirement of any externally applied cinching force.The shape memory material can be characterized by its transitiontemperature (Af temperature) separating the cold, deformable state(martensitic phase) from the warm state (austenitic phase) where thecomponent springs back to its original shape. The Af temperature of theshape memory material could be set in such a range (e.g., between 40° C.and 60° C.) that the outer device is inserted into position in theanatomy in its cold, deformable state (martensitic phase) so as toenable delivery through the tortuosities of the vasculature and adequatepositioning without resistance. It could then be heated beyond the Aftemperature, for instance by an electric current, so as to conform toits original shape in its warm state (austenitic phase). Its originalshape could be set in such a way that upon recovering this shape aftercold deformation and upon heating, a freeze mechanism like a ratchet oranchoring becomes active for instance enabling the two ends of the outerdevice to become connected. This feature would enable the outer deviceto maintain its shape and position despite partially cooling down againafter the heating action is stopped.

The inner device and the outer device may be separated from each otherand may be not in a physical contact with each other. However, the innerand outer devices may also include projections projecting toward eachother and penetrating the tissue of the circumferential connectionchannel wall structure clamped in-between, wherein the penetratingprojections of the inner and outer devices may come in contact with therespective other one of the inner and outer devices.

The inner device, for example its circumferential support structure,extends along an axis along the through opening therethrough (followingthe direction of the native connection channel or through openingthrough the native atrio-ventricular valve), and the outer device, forexample provided as a ring, may be arranged at a position along saidaxis, that is between the axial ends of the inner device, for examplebetween the ends of the circumferential support structure, to thereby bearranged in a distance (axial distance) from these ends. The innerdevice, for example its circumferential support structure, may have anelongate shape so that said axis may be the longitudinal axis and theends may be the longitudinal ends.

The inner and outer devices may also include means for engaging thecircumferential connection channel wall structure from the respectiveinner and outer peripheries thereof. In this respect, the inner device,for example its circumferential support structure, may comprise barbs,hooks, anchor part(s), or other projections for penetrating into thecircumferential connection channel wall structure from the interiorthereof. Correspondingly, the outer device may include such projectionsfor correspondingly penetrate into the circumferential connectionchannel wall structure.

On the other hand, the inner device may also be free of projections ator on its outer surface (outer circumferential surface).

Further, the outer device formed by a wire or ribbon may also be atleast partially interwoven into the chordae tendinae structure tothereby internally extend therearound, but still in a radial distance tothe inner device and its circumferential support structure arranged onthe inner periphery of the circumferential connection channel wallstructure.

The inner device, for example its circumferential support structure, maybe provided with an outer circumferential or peripheral indentation, forexample a groove, for example with a V-shaped or U-shaped cross-section,and the outer device may comprise a closed or open ring engaging theindentation, for example the groove, with the connection wall channelstructure clamped therebetween. The width of the groove, for example ofthe U-shaped groove, may be substantially adapted/substantiallycorrespond to the cross-sectional dimension of the ring (ring wall) ormay be slightly greater such as to still allow tissue of thecorresponding wall structure portion of the circumferential connectionchannel wall structure to be pressed into the groove following thegroove's cross-section, for example the U-shaped cross-section thereon,and laterally pressed against the lateral walls of the groove, and forexample additionally pressed against the bottom/base of the groove, forexample pressed against the base and/or laterally pressed against thelegs of the U-shaped cross-section. The circumferential groove may be acontinuously circumferentially extending groove or may extendcircumferentially in an interrupted manner. The groove may be formed by(between) adjacent rips which radially protrude from the outer surfaceof the inner device (such as from its circumferential support structure)and which circumferentially, for example in a continuous or interruptedmanner, extend around the inner device (such as around itscircumferential support structure). The groove may also be formed byadjacent rows of separated projections (such as bosses) which radiallyprotrude outwardly from the outer surface of the inner device (such asfrom the outer surface of the circumferential support structure). Thegroove may also be formed as circumferentially extending (for example ina continuous manner) recess provided in the otherwise smooth orprojection-free outer surface of the inner device (such as of thecircumferential support structure).

The inner device, for example its circumferential support structure, maybe provided with an outer circumferential projection (rib-likeprojection) as the outer circumferential indentation, and the outerdevice may comprise one or two rings arranged adjacent to and (in caseof two rings) on opposite (axial) sides of the outer circumferentialprojection.

The inner device, for example its circumferential support structure, maybe provided, on its outer periphery, with a compressible material or acompressible structure (the compressible material/structure may bedifferent from the material of the circumferential support structure),such as a foam material, for example as a coating or coating structureor surface structure/material, wherein the outer device, for example thering shaped outer device, then may locally compress said compressiblematerial, for example along the circumference of the ring of the outerdevice, to thereby form a corresponding (circumferential) groove in thecompressible material.

The inner device may further have a funnel shape to approach the funnelshape of the connection channel/through opening through the native valveannulus and native valve leaflets of the atrio-ventricular valve in thearea of the native valve annulus.

The implantation procedure may be carried out under variousvisualization means, such as: angiography, echography (Trans EsophagealEcho, Trans Thoracic Echo, Intra Cardiac Echo), MRI.

The catheter(s) for forwarding the inner and outer devices may, forexample, be inserted by any of the following paths for treatment of themitral valve: 1) over an arterial retrograde approach entering the heartcavity over the aorta, 2) through a venous access and through a puncturethrough the inter atrial septum (trans-septal approach), 3) over apuncture through the apex of the heart (trans-apical approach) or 4)over a puncture through the atrial wall from outside the heart.

The catheter(s) for forwarding the inner and outer devices may, forexample, be inserted by any of the following paths for treatment of thetricuspid valve: 1) over an arterial retrograde approach entering theheart cavity over the pulmonary artery following a surgical access ofthe later, 2) through a venous access, 3) over a puncture through theapex of the heart (trans-apical approach) or 4) over a puncture throughthe atrial wall from outside the heart.

A possible access for delivering the outer device, for example the wire,ring or snare, is an arterial access (e.g., the femoral artery through apuncture in the groin). A guide-wire may be advanced over the aortathrough the aortic valve inside the left ventricle. Over the guide-wire,a guiding catheter can be advanced. The catheter may be pre-shaped onits distal end with an angle of approximately 90° in such a way that itenables positioning of the guide-wire in the sub-annular groove (thespace bellow the mitral annulus and between the ventricular wall and theposterior leaflet). Over the guide-wire and inside the guiding catheter,a second pre-shaped catheter can be advanced that will, upon exiting theguiding catheter, position itself around the posterior leaflet insidethe sub-annular groove. Advancing the guide-wire inside that pre-shapedcatheter allows it to travel around the posterior and the anteriormitral leaflet. A second lumen inside the guiding catheter (for examplein form of a second catheter, or a second catheter) allows positioningof a snare to catch the guide-wire after its loop around the nativevalve leaflets, whereby the native valve leaflets are caught in a lassomanner.

Optionally a catheter can be threaded over the guide-wire to position ananchor (member) inside the ventricular wall or the annulus close toselected areas like the middle of the posterior leaflet. This anchor(member) allows maintenance of the relative height of the guide-wire soas to avoid grabbing the native leaflet too low. It also allows theapparatus to favor the final position of the stent-valve, that is, theinner device with its circumferential support structure and valve,within the mitral annulus plane close to the posterior wall so as forinstance to grab a greater length of the posterior leaflet.

In embodiments, the guide-wire can be exchanged for a different kind oflasso with additional features (e.g., greater contact surface, barbs onits surface, shape memory). In addition, if the custom made lasso doesnot already provide for it, a stopping device can be advanced so as toclose the loop and freeze it at a given circumference optimal forstent-valve anchoring.

The outer device, for example formed as a ring, such as a wire ring orsnare ring, may be positioned around the native leaflets in such a waythat it wraps those leaflets around the deployed inner device. The ringcan be positioned at different heights, wherein a (height) positionproviding an improved sealing function may be seen to be a position asclose as possible to the native valve annulus. In this regard, thenative leaflets are used to anchor the atrio-ventricular (mitral) valveprosthesis as well as to achieve peri-prosthetic sealing. Preferably,the ring is inserted around the native valve annulus so as to bepositioned above the chordae tendinae to provide an improved sealingfunction.

The outer device, for example, formed as a ring, such as a wire ring orsnare ring, may be fixed into place, and thus remain attached inside theheart upon completion of the implantation of the atrio-ventricular(mitral) valve prosthesis. Alternatively, the wire ring or snare ringmay be used to position the native leaflets in a selected area toactivate an anchoring mechanism, and may be subsequently removed. Thatis, in some embodiments, the wire ring or snare ring may be used onlyduring the implantation procedure.

According to an aspect of the invention, the outer device, for examplein addition to the ring thereof, may further comprise one or morestaples arranged around the periphery/circumference of the inner deviceand each having a base member arranged in a radial distance to andoutwardly of the inner device to clamp the circumferential connectionchannel wall structure between the base member and the inner device andeach having penetration legs for penetrating the circumferentialconnection channel wall structure and engaging the inner device, forexample the circumferential support member thereof, for being fixedthereon and for providing the clamping force between the base member andthe inner device.

According to an aspect of the invention, for example in addition to thering and/or in addition to the staples of the outer device, the outerdevice may comprise one or more clips arranged around the outercircumference or outer periphery of the inner device and having aU-shape with a base portion and two legs extending from the baseportion, one of the legs extending in a radial distance to and outwardlyof the inner device, the other one of the legs engaging the innerdevice, for example by engaging the circumferential support member at aninner peripheral/circumferential side thereof, and the base portion maybe arranged at a free front end of the native valve leaflets, wherebythe clip(s) (axially) extend around the free front end of the nativevalve leaflets, and the legs clamp the circumferential connectionchannel wall structure, formed by the leaflets in this area, and thecircumferential support structure together, whereby the circumferentialconnection channel wall structure (here, the native valve leaflets) ispositioned between the one clip leg and the circumferential supportmember of the inner device.

The above-mentioned clips or staples can be inserted through theleaflets to the inner device (clipping from the ‘outside’), or throughthe inner device to the leaflets (clipping from the ‘inside’). In thelatter case, the base member of the respective staple is arranged on aninner peripheral side of the inner device, for example of thecircumferential support member, and the penetration legs of the staplepenetrate the circumferential connection channel wall structure from aninner side to an outer side, with the free end of the penetration legsextending in a radial distance outwards of the inner device therealongor therearound, whereby the circumferential connection channel wallstructure is clamped between the free ends of the penetration legs andthe inner device.

In case of using the above-mentioned clips and/or staples arranged inangular intervals around the circumference of the inner device, theclamping mechanism can correspondingly clamp in a non-continuous(interrupted) circumferential manner.

As an alternative to the outer device, or in addition to the outerdevice, the inner device may comprise anchors or hooks fixed to theinner device and extending therefrom to be positioned inside the heartmuscle (papillary muscle or ventricular wall) to enable the inner deviceto further resist the back pressure. In this respect, for example, theouter device may comprise elongate anchor elements which extend from theinner device by a (axial) distance so as to be able to penetrate withfree ends thereof into native papillary muscle(s) when the inner deviceis in a finally implanted position within the connection channel.

Further, the inner device itself may contain components to facilitateits inherent anchoring such as hooks, barbs, an adhesive surface (e.g.,biological glue), arms or cuffs to wrap around the native leaflets orthe chordae tendinae or combinations thereof. According to an aspect ofthe invention, for example in addition to the ring and/or in addition tothe staples and/or in addition to the clips, the outer device maycomprise one or more arms extending at the outer periphery of the innerdevice in a radial distance thereto, to thereby be able to clamp thecircumferential connection channel wall structure radially between thearm(s) and the inner device, the arms, starting from a free end thereof,(axially) extend in parallel to the inner device (for example, thecircumferential support structure thereof) to thereby form acorresponding radial gap therebetween for receiving the circumferentialconnection channel wall structure therein for being clamped, and extendtowards the inner device (for example, the circumferential supportstructure thereof) to be connected thereto, for example at an axial endof the inner device (e.g., of the circumferential support structurethereof). Thereby, the arms distributed around the outer periphery ofthe inner device form a collar therearound for radially wrapping thefree ends of the native valve leaflets and for radially clamping the(free ends of the) native valve leaflets in the radial gap between theradial inner side of the collar and the inner device (for example thecircumferential support member).

FIG. 1 shows a transcatheter atrio-ventricular valve prosthesis 1according to an embodiment of the invention, implanted between leftatrial and ventricular chambers 3, 5 of a human heart 7 to replace the(function of the) native mitral valve 9 as the native atrio-ventricularvalve between said left atrial and ventricular chambers 3, 5. The nativemitral valve 9 comprises a native valve structure including native valveleaflets 11, a native valve annulus 13, native chordae tendinae 15, andnative papillary muscle(s) 17. The native valve annulus 13, the nativevalve leaflets 11, chordae tendinae 15 and the papillary muscle(s) 17form a connection channel 18 between the atrial and ventricular chambers3, 5, and said connection channel 18 has a circumferential connectionchannel wall structure 18′.

The valve prosthesis 1 of FIG. 1 comprises an inner device 19 with acircumferential support structure 21 in form of an elongate tubularmesh-like body, within which a valve 22 in form of a three-flapstructure is arranged and attached/fixed, for example non-detachablyattached, to the circumferential support structure 21. The (new) valve22 and, hence, its flap structure is provided such as to close areplacement connection opening/replacement connection channel providedthrough or interiorly defined by the circumferential support structure21, here along the longitudinal axis of the circumferential supportstructure 21, when the left ventricular chamber 5 is contracted, and toopen said replacement connection channel when the left ventricularchamber 5 is expanded. In this case, the inner device 19 with itscircumferential support structure 21 and its valve 22 therewithin isarranged in-between the native leaflets 11 as well as within the nativevalve annulus 13 and, thus, within the (native) connection channel 18 inphysical and circumferential contact with the inner side of thecircumferential connection channel wall structure 18′ thereof.

The circumferential support structure 21 is radially compressible tothereby be insertable into the mitral valve 9 by means of a catheter 23via a percutaneous approach. When in place in the interior of theconnection channel 18, the circumferential support structure 21 isbrought from its collapsed condition into a deployed conditioncircumferentially abutting, for example pressing, against the innerperiphery of the circumferential connection channel wall structure 18′of the connection channel 18 of the native atrial valve 9, here againstthe inner periphery of both the native valve leaflets 11 and the nativevalve annulus 13.

The valve prosthesis 1 further comprises an outer device 25 in form ofor comprising a wire ring 26 or snare ring 26 disposed on and extendingcompletely around an exterior or outer side of the connection channel 18and of the circumferential connection channel wall structure 18′thereof, here, around the native valve leaflets 11 at a position closeto the valve annulus 13 and between longitudinal ends of thecircumferential support structure 21 of the inner device 19. In thisembodiment, the outer device 25 is separate from the inner device 19 andis not in physical contact therewith. The ring-shaped outer device 25thereby circumferentially extends around the inner device 19 in a radialdistance thereto, wherein the circumferential connection channel wallstructure 18′, here the circumferential connection channel wall formedby the native valve annulus 13 and the native valve leaflets 11, isclamped between the inner and outer devices 19, 25 which thereby form aclamping mechanism for continuously circumferentially clamping theconnection channel wall structure 18′ therebetween.

The wire ring 26 of the outer device 25 may be elastically ornon-elastically contractible so as to be able to add additional activeclamping force from radially outside of the valve structure 11, 13, 15,17 thereagainst. The wire material of the wire of the outer device 25may be linearly forwarded to the exterior of the circumferentialconnection channel wall structure 18′ via a catheter 27 forwarded via apercutaneous approach.

As can be further seen in FIG. 1, the elongated tubular shapedcircumferential support structure 21 of the inner device 19 extendsalong a (longitudinal) axis which in turn extends along the longitudinalaxis of the connection channel 18 (axis extending across to the throughopening between the atrial chamber 3 and the ventricular chamber 5),whereby the circumferential support structure 21 correspondingly has(two) axial ends 21′, 21″. At one of the axial ends 21′, 21″, which isproximal to the native valve annulus 13, the circumferential supportstructure is formed in a funnel shape (defining a funnel portion 24) toapproach the native funnel shape of the connection channel 18 in thearea of the native valve annulus 13. The ring-shaped outer device 25 isarranged at a (an axial) distance from the axial ends 21′, 21″therebetween and, thereby, at an axial distance from the funnel portion24.

In FIGS. 2A to 2E an approach for implanting the prosthesis 1 accordingto FIG. 1 will now be explained.

As can be seen from FIGS. 2A to 2C, firstly the catheter 27 is forwardedto the left ventricular chamber 5 via the aorta and the aorta valve 29,and is then guided around the circumferential connection channel wallstructure 18′ of the connection channel 18, at the level (height) of thenative valve leaflets 11 close to the native annulus 13, of the mitralvalve 9 to be functionally replaced by the prosthesis 1. That is, thecatheter 27 is guided around the circumferential connection channel wallstructure 18′ of the connection channel 18 and not around the chordaetendinae, which could otherwise undesirably result in the ring-shapedouter device 25 being caught on or placed between chordae tendinae. Aflexible and non-elastic wire 25′ which will form the ring 26 of theouter device 25 is guided through the catheter 27 and, thereby, isguided around the outer circumference of the circumferential connectionchannel wall structure 18′ at the corresponding level of the nativevalve leaflets 13. The catheter 27 is then slightly retracted and thewire 25′ is then provided as contractible loop 31 (lasso type) having adiameter greater than the (cross-sectional) outer diameter of thecircumferentially extending connection channel wall structure 18′ andgreater than the diameter of the final ring 26 of the outer device 25.The loop 31 thereby extends around the connection channel 18 at a radialdistance thereto, that is, at a radial distance to the connectionchannel wall structure 18′, and allows the inner device 19 to beappropriately inserted into the inner side/interior of the connectionchannel 18.

In order to catch the free end 25″ of the wire 25′ and to thereby formthe loop 31, a catching wire or additional lasso wire, having acontractible catching snare 28 at its distal end, is forwarded throughthe catheter 27. By means of said snare 28 of the catching wire the freeend 25″ of the wire 25′ is caught and drawn into the catheter 27 tothereby form the loop 31 formed by the wire 25′, which loop then can befurther contracted to closely circumferentially engage the connectionchannel wall structure 18′. Instead of the shown snare 28, a catchingbasket (not shown) may be used for catching the free end 25″ of the wire25′, which is provided on the snare or lasso wire. Such a catchingbasket may, for example, be formed as a tubular member provided withlongitudinal slots, wherein the tubular member can be axially contractedto laterally widen the longitudinal slots, in order to receive the freeend 25″ within one or more of the longitudinal slots, and can be axiallyre-extended (after axial contraction) to thereby laterally narrow/closethe previously widened slots to thereby catch/fix the free end 25″ ofthe wire 25′ therein. It is to be noted that other catchingmechanisms/catching devices may be used, instead of the catching snareor catching basket, to catch or grip the free end of the wire 25″, suchas any gripping device, such as a gripper device or forceps.

As can be seen from FIG. 2D, the catheter 23 is then forwarded to theleft atrial chamber 3 via a puncture 33 through the inter atrial septum,and the inner device 19 with its circumferential support structure 21and the (new or replacing) valve 22 therein is forwarded in itscollapsed condition through the catheter 23 to be disposed in-betweenthe native leaflets 11 and the native annulus 13 forming part of theconnection channel 18. Then the circumferential support structure 21 isdeployed by either radial self-expansion or radial expansion by meansof, for example, an inflatable balloon inserted into the interior of thecircumferential support structure 21, whereby the circumferentialsupport structure 21 radially and outwardly presses against the innerperiphery of the circumferential connection channel wall structure 18′in the area of and at the level of the native valve annulus 13 and thenative valve leaflets 11. As can be seen from FIG. 2E, the loop 31 isthen contracted to provide a radial counter-force against the radialforce provided by the inner circumferential support structure 21, actingradially and inwardly against the circumferential outer periphery of thecircumferential connection channel wall structure 18′ at a level of thenative valve leaflets 11 adjacent to the native valve annulus 13.Thereby, the connection channel wall structure 18′ of the connectionchannel 18 and, for example in this case, the native valve leaflets 11and the native valve annulus 13, is prevented from being inappropriatelyradially expanded and is circumferentially clamped in-between thecircumferentially extending loop 31 and the circumferential supportstructure 21 of the inner device 19. Finally the diameter of the loop 31is fixed to thereby finalize the ring 26 forming the outer device 25 inthis case, and thereby finalizing the implantation of theatrio-ventricular (here mitral) valve prosthesis 1 as shown in FIG. 1.

In sum, with respect to FIGS. 2A-2E, the loop 31 is first positionedaround the native valve annulus 13. Afterward, the inner device 19 withits circumferential support structure 21 and the valve 22 therein isforwarded in its collapsed condition through the catheter 23 to bedisposed in-between the native leaflets 11 and the native annulus 13forming part of the connection channel 18. Next, the loop 31 istightened to pull the native leaflets 11 toward the inner device 19,which is expanded from the collapsed condition. The loop 31 can theneither be frozen in position and then removed once the inner device 19is secure, or the loop 31 may be non-frictionally employed to positionthe inner device 19 and allow another form of anchoring to be activated,and then the loop 31 is subsequently removed.

FIG. 3 shows an atrio-ventricular valve prosthesis 1 according toanother embodiment of the invention. According to this embodiment, thecircumferential support structure 21 of the inner device 19 is providedwith an indentation in the form of an outer circumferential groove 35,and the ring-shaped or snare-shaped outer device 25 is arranged to be(axially) aligned to the outer circumferential groove 35. That is, thering-shaped outer device 25 is arranged at the level of the outercircumferential groove 35 to thereby force the corresponding area of thenative valve leaflets 11 and, hence, the corresponding area of theconnection channel wall 18′ of the native mitral valve 9 radially intothe outer circumferential groove 35 as a result from clamping the saidarea of the circumferential connection channel wall structure 18′between the outer and inner devices 25, 19. The circumferential groove35 may allow for a use of the ring-shaped outer device 25 that does notinvolve frictionally securing the prosthesis in place. That is, thering-shaped outer device may, upon tightening, be loosely positionedwithin the circumferential groove 35 to ensure proper positioning of theatrio-ventricular valve prosthesis 1 (see FIG. 15) until the innerdevice 19 is secured to the circumferential connection channel wallstructure 18′ with, for example, sutures, staples, barbs, adhesives oranother anchor mechanism.

As can be further seen in FIG. 3, the circumferential support structure21 of the inner device 19 is of an elongated tubular shape and extendsalong an axis which in turn extends along the longitudinal axis of theconnection channel 18 (axis extending cross to the through openingbetween the atrial chamber 3 and the ventricular chamber 5), whereby thecircumferential support structure 21 correspondingly has (two) axialends 21′, 21″. At one of the axial ends 21′, 21″, which is proximal tothe native valve annulus 13, the circumferential support structure isformed in a funnel shape (defining a funnel portion 24) to approach thenative funnel shape of the connection channel 18 in the area of thenative valve annulus 13. The funnel shape of the funnel portion 24 canminimize or prevent one way migration of the circumferential supportstructure 21 of the inner device 19. The circumferential supportstructure 21 of the inner device 19 may also have hooks, barbs or someother anchor mechanism that prevents migration of the circumferentialsupport structure 21 of the inner device 19, at least in an oppositedirection from that prevented by the funnel portion 24. The ring-shapedouter device 21 and correspondingly the groove 35 aligned therewith arearranged in a distance (axial distance) from the axial ends 21′, 21″between the axial ends 21′, 21″ and, thereby in an axial distance fromthe funnel portion 24.

FIG. 4 shows an implantation approach, according to which both catheters23, 27 for forwarding the inner device 19 and the outer device 25,respectively, are forwarded to the native mitral valve 9 via the atrium3 and a puncture 37 through the atrial wall from outside the heart.Instead of the puncture 37, the atrium 3 may also be surgicallyaccessed, wherein the access may be carried out on a beating heart or onan arrested heart.

FIG. 5 shows an implantation approach, according to which the catheter23 for forwarding the inner device 19 to the native mitral valve 9 isforwarded via the left atrial chamber 3, and the catheter 27 forforwarding the outer device 25 to the native mitral valve 9 is forwardedvia a puncture 39 through the apex of the heart (trans-apical approach).

FIG. 6 shows an embodiment of the invention, according to which theouter device 25, for example in addition to the ring-shaped device 25 ofFIG. 1, additionally or only comprises a plurality of staples arrangedaround the periphery of the inner device 19. The inner device 19 isprovided as tubular stent as described in connection with the embodimentof FIG. 1 so that it is referred to the corresponding description above.The respective staple has a base member 41 extending in a radialdistance to the circumferential support structure 21 of the inner device19 at a radial outer side thereof to thereby clamp the circumferentialconnection channel wall structure 18′ (here, the native valve leaftlets15) radially between the base member 41 of the staple and the innerdevice 19 with its circumferential support member 21 and valve. Theradial clamping force is in this case achieved by penetration legs 43radially penetrating the circumferential connection channel wallstructure 18′ (here, the native valve leaftlets 15) from the outsidetowards the inside and engaging the mesh-structure of thecircumferential support structure 21 to thereby radially andperipherally draw said circumferential support structure 21 towards therespective staple base member 41 with the circumferential connectionchannel wall structure 18′ (here, the native valve leaflets 15) clampedtherebetween.

FIG. 7 shows an embodiment of the invention, according to which theouter device 25, for example in addition to the ring-shaped device 25 ofFIG. 1 and/or in addition to the staples of FIG. 6, additionally or onlycomprises a plurality of clips or clamps arranged around the outerperiphery of the inner device 19 at the free ends of the native valveleaflets 11 and at an axial end of the inner device 19. The inner device19 is provided as a tubular stent as described in connection with theembodiment of FIG. 1 so that it is referred to the correspondingdescription above. The respective clip is generally of U-shape with aU-base portion 51 and two U-leg portions 53, 55. The clips are arrangedsuch as to respectively encompass the free end of the native valveleaflets 11 and the axial front end of the tubular inner device 19,wherein an outer leg portion 55 of the leg portions 53, 55 extends in aradial distance to the inner device 19 along the axial direction thereofand is in a clamping contact with the radial exterior side of thecircumferential connection channel wall structure 18′ (here, the nativevalve leaflets 15), and an inner leg portion 53 extends along the axialdirection of the inner device 19 (along the circumferential supportstructure 21) and is in a clamping contact therewith, whereby the innerdevice 19 (including the circumferential support structure 21 thereof)and the connection channel wall structure 18′ (here, the native valveleaflets 15) are radially clamped between the leg portions 53, 55 of therespective clip.

FIG. 8 shows an embodiment of the invention, according to which theouter device 25, for example in addition to the ring-shaped device 25 ofFIG. 1 and/or in addition to the staples and/or clips of FIGS. 6 and 7,additionally or only comprises a plurality of arms extending around theouter circumference/periphery of the inner device 19 in a radialdistance thereto, to clamp the circumferential connection channel wallstructure 18′ radially between the arm(s) and the inner device 19, thearms, starting from a free end 61 thereof, extend in parallel to theinner device 19 (for example, the circumferential support structurethereof 21) to thereby respectively form a corresponding radial gap 63therebetween for receiving the circumferential connection channel wallstructure 18′ (here the free ends of the valve leaflets 11) therein forbeing clamped, and extend towards the inner device 19 (for example, thecircumferential support structure 21 thereof) and are fixedly connectedto the inner device 19 at an axial end thereof. Thereby, the arms 25distributed around the outer periphery of the inner device 19 form anangularly interrupted collar 65 therearound for radially wrapping theconnection channel wall structure 18′ (here, the free ends of the nativevalve leaflets 13) and for radially clamping the connection channel wallstructure 18′ (here, the free ends of the native valve leaflets 13) inthe radial gap 63 between the radial inner side of the collar 65 and theinner device 19 (for example the circumferential support member 21). Theinner device 19 is provided as a tubular stent as described inconnection with the embodiment of FIG. 1 so that it is referred to thecorresponding description above.

FIG. 9 shows an embodiment of the invention, according to which inaddition to the outer device 25 or, for example, as an alternativethereto, the inner device 19, which is provided as a tubular stent asdescribed in connection with the embodiment of FIG. 1, compriseselongate anchor elements 71, for example in form of elongate wireanchors provided with hooks or barbs 73 at free ends 75 of the anchorelements 71, which anchor elements 71 axially extend from the innerdevice 19 by a distance so as to be able to penetrate with their freeends 75 into the native papillary muscle(s) 17, when the stent-typeinner device 19 is in its finally implanted position within the nativemitral valve 9, for example between the native valve leaflets 11thereof.

In all aspects of the invention, the (new/replacing) valve attached tothe circumferential support structure of the stent-type inner device maycomprise a circumferential wall portion which is circumferentially andradially clamped as part of the inner device against the inner peripheryof the circumferential connection channel wall structure of the nativeatrial-ventricular valve to thereby provide for further improved sealfunction between the circumferential connection channel wall structureand the inner device. The outer device may be arranged aligned to or ata level of said circumferential wall portion of the (new/replacing)valve to thereby provide the clamping force at the level of or at leastclose to said circumferential wall portion of the valve.

FIG. 10 shows an approach for implanting a transcatheteratrio-ventricular valve prosthesis 1 within the native tricuspid valve9′ for replacing the function thereof. The prosthesis 1 according tothis embodiment is identical to the prosthesis according to FIG. 1 sothat regarding the structure of the prosthesis of FIG. 10 it is referredto the description of the embodiment of FIG. 1. The native tricuspidvalve 9′ defines a connection channel 18, having a circumferentialconnection channel wall structure 18′, fluidly connecting the rightatrial and ventricular chambers 3′, 5′.

As can be seen from FIG. 10, the inner device 19 is forwarded to thetricuspid valve 9′ via the superior vena cava 81, connected to the rightatrium 3′, by means of a catheter 23, and the outer device 25 isforwarded to the exterior of the connection channel 18, that is to theright ventricular chamber 5′ and, thus, to the exterior of thecircumferential connection channel wall structure 18′, via the inferiorvena cava 83 and a passage 85 between the leaflets 11′ of the tricuspidvalve 9′. Alternatively, the catheter 23 with the inner device 19 may beforwarded via the inferior vena cava 83, and the catheter 27 with theouter device 25 may be forwarded via the superior vena cava 81, or bothcatheters 23, 27 may be forwarded via the same one of the superior venacava 81 and inferior vena cava 83. For introducing the catheters 23, 27into the veins 81, 83 or, in case of a mitral valve prosthesis asdescribed above, into the aorta, femoral, cervical and/or thoracicaccesses may be used as appropriate and/or as presently known for otherheart catheter applications, such as for the application of known heartcatheter probes. Further, the catheter 23 with the inner device 19 mayalso be forwarded to the tricuspid valve 9′ via a puncture (not shown)through the right atrium 3′ or via a surgical access to the right atrium3′, which may be carried out on the arrested or beating heart. Thecatheter 27 with the outer device 25 may also be forwarded via apuncture (not shown) through the right ventricular chamber 5′.

FIG. 11A shows a perspective sectional view of a further embodiment ofthe invention, and FIG. 11B shows a section along line B-B in FIG. 11A.The embodiment shown in FIGS. 11A and 11B substantially corresponds tothe embodiment of FIG. 3, wherein, however, the ring 26 forming theouter device 25 is not a closed ring but an open ring havingnon-connected or non-interconnected free ends 25′, 25″ (cf. FIG. 11B).The ring-shaped outer device 25 is arranged at the (axial) level of thegroove 35 provided in and circumferentially extending around the innerdevice 19 (that is, provided in and extending around the circumferentialsupport structure 21 of the inner device 19). That is, the ring 26forming the outer device 25 is aligned with the circumferential groove35. The section, shown in FIG. 11B, extends centrally through and alongthe groove 35. Regarding the further details of the embodiment of FIGS.11A and 11B, it is referred to the above explanation of the embodimentof FIG. 3.

FIGS. 12A-12J schematically show an approach for implanting aring-shaped outer device 25 (cf. FIG. 12) J of a transcatheteratrio-ventricular valve prosthesis 1, as for example described above,according to an embodiment of the invention.

As can be seen from FIGS. 12A and 12B, a first delivery catheter 100 anda second delivery catheter 102, which are separate from each other(separate catheters) and, hence, which do not create a single interiorbut separate interiors, are forwarded to the ventricular chamber 5 (herethe left ventricular chamber) of the heart 7 for example via the aorta(here) or for example via the superior or inferior vena cava (in case ofright ventricular chamber). The first and second delivery catheters maybe forwarded via a (same) primary delivery catheter 104 providing theprimary access to the ventricular chamber 5 via the aorta or the venacava.

As can be seen from FIG. 12F and FIG. 12E a wire 25″ is guided aroundabout a circumferential portion, for example about the halfcircumference, of the circumferential connection channel wall structure18′ of the connection channel 18 via the first delivery catheter 100 inone circumferential direction of the circumferential connection channelwall structure 18′, and a catching snare wire 106 with a catching basket108 at a front end thereof (alternatively, for example, a catching snare28 as shown in FIGS. 2A and 2B may be used instead of the catchingbasket 108) is guided around about the remaining circumferentialportion, for example about the other half circumference, of thecircumferential connection channel wall structure 18′ of the connectionchannel 18 via the second delivery catheter 102 in the othercircumferential direction of the circumferential connection channel wallstructure 18′, wherein the free end 25″ will be guided through the threedimensional structure of the catching basket 108 (or through thetwo-dimensional opening of the catching snare 28) so as to be able to becaught by the catching basket 108 (or the catching snare 28).

The wire 25″ and/or the catching wire 106 may be guided around thecircumferential connection channel wall structure 18′ by means of firstand second auxiliary delivery catheters 110, 112, respectively, whichauxiliary delivery catheters 110, 112 may have been previously forwardedthrough the first and second delivery catheters 100, 102 and may be of ashape-memory material provided to return the first and second auxiliarydelivery catheters 110, 112 to assume a bow shape to be correspondinglyable to automatically surround the circumferential connection channelwall structure 18′ when being exposed from the first and second deliverycatheters 100, 112. Accordingly, as can be seen from FIGS. 12C and 12D,the first and second auxiliary catheters 110 and 112 may be forwardedaround the circumferential connection channel wall structure 18′ beforeforwarding the wire 25′ and the catching wire 106 therethrough.

As can be seen from FIG. 12G-12J, with the free end 25″ of the wire 25′reliably caught in the catching basket 108 (or catching snare 28), thecatching wire 106 is retracted back through the second delivery catheter102 thereby guiding the wire 25′ further around, for example completelyaround, the circumferential connection channel wall structure 18′ tothereby form the loop 31 (also cf. FIG. 2C) to be further contracted tofinally form the ring shaped outer device 25 or the device comprisingthe ring 26. The first and second auxiliary catheters 106, 108 may beretracted through the first and second delivery catheters 100, 102 (cf.FIGS. 12G and 12H) and then the first and second delivery catheters 100,102 may be retracted (cf. FIG. 121) through the primary deliverycatheter 104 which itself may be retracted at latest. The inner devicemay be installed within the connection channel 18 in a manner asdescribed above.

FIGS. 13A and 13B schematically show a perspective sectional side viewand a perspective sectional top view of a transcatheteratrio-ventricular valve prosthesis 1 for functional replacement of anatrio-ventricular valve 9 in a connection channel 18, having acircumferential connection channel wall structure 18′, between theatrial chamber 3 and the ventricular chamber 5 of a heart 7. Theprosthesis comprises an inner device 19 (which may have a structure in amanner as the inner devices as explained above) to be disposed in theinterior of the connection channel 18, the inner device 19 having acircumferential support structure 21 (which may have a structure in amanner as the circumferential support structures as explained above)which is radially expandable, and having a valve (which may have astructure in a manner as the valves as explained above) attached to thecircumferential support structure 21. The circumferential supportstructure 21 of the inner device 19 is of tubular shape and extendsalong an axis and has two axial ends 21′, 21″, and an outer device 25(which may generally have a structure in a manner as the outer devicesas explained above) to be disposed on the exterior of the connectionchannel 18 (that is, of the circumferential connection channel wallstructure 18′). The outer device 25 at least partly extends around theinner device 19 in a radial distance to the inner device 19, and wherebythe inner and outer devices 21, 25 form a clamping mechanism forclamping the circumferential connection channel wall structure 18′therebetween. The outer device 25 comprises a ring 26, for extendingcircumferentially around the circumferential connection channel wallstructure 18′, arranged between and in a distance to the axial ends 21′,21″ of the inner device 19. The outer device 25 further comprises ananchor member 150 having one or more anchor parts 152, such as barbs orhooks, to penetrate into the circumferential connection channel wallstructure 18′ at a position close to the ring 26. The anchor member 150comprises an eye 154, through which the ring 26 extends to thereby beanchored on the circumferential connection channel wall structure 18′ atthis position by the anchor member 150. The eye 154 may have athree-dimensional catching basket structure as for example shown for thecatching basket 108 in FIG. 12E.

FIGS. 14A and 14B schematically show a sectional side view and asectional top view, respectively, illustrating an approach forimplanting the transcatheter atrio-ventricular valve prosthesis 1according to the embodiment of FIGS. 13A and 13B. As can be seen fromFIG. 14A, regarding implantation of the outer device 25, as a firststep, the anchor member 150 may be delivered to the ventricular chamber5 and penetrates with its anchor part or parts 154 into thecircumferential connection channel wall structure 18′, for example at aposition at or adjacent to the annulus native valve annulus 13. With theanchor member 150 anchored in this position, the wire 25′ may be guidedaround the circumferential connection channel wall structure 18′ in amanner as described above to form the ring 26 of the outer device 25,wherein the wire 25′ is guided through the eye 154 of the anchor member150, whereby the wire 25′ and the finalized ring 25 and thereby theouter device 126 are reliably positioned and fixed/anchored to thecircumferential connection channel wall structure 18′. The inner device(not shown in FIGS. 14 and 14B) may be structured in any shape asdescribed above and may be implanted according to any approach asexplained above. On the basis of the structure of this embodiment, as analternative aspect to clamping the circumferential connection channelwall structure 18′ between the inner device 19 and the outer device 25,the inner device 25 may be fixed to the inner side of thecircumferential connection channel wall structure 18′ only by means ofone or more anchor elements attached on the circumferential supportstructure and fixed to the circumferential connection channel wallstructure 18′ for example via penetrating the circumferential connectionchannel wall structure 18′ and/or clamping, for example in manner asachieved by the staples 41, 43 as described above (cf. for example FIG.6), the clips 51, 53, 55 as described above (cf. for example FIG. 7),the collar 65 as described above (cf. for example FIG. 8), the anchorelements 71 as described above (cf. for example FIG. 9) and/or othersuitable anchors and for example in combination with the funnel portion24 as described above (cf. for example FIG. 3). The outer device 25, forexample the ring 26, may then not provide for a sufficient clampingaction to secure inner device 19 within the connection channel 18, butmay only provide for such a clamping force (in connection with thecounter-force provided from the inner device 19) that a sealingeffect/function is achieved between the circumferential connectionchannel wall structure 18′ and the inner device 19 (the circumferentialsupport structure 21 thereof).

FIG. 15 shows a sectional side view in which the outer device 25 isemployed to position the outer device 25 within the circumferentialgroove 35 to ensure proper positioning of the atrio-ventricular valveprosthesis 1 without frictionally securing the atrio-ventricular valveprosthesis 1 in place.

Various figures herein illustrate that the ring 26 of the outer device25 remains positioned around the inner device 19 upon completion of theimplantation of the atrio-ventricular (here mitral) valve prosthesis 1.However, the ring 26 of the outer device 25 can in embodiments beremoved upon completion of the implantation. In such a case, the ring 26of the outer device 25 may be used only during the implantationprocedure to position the native valve leaflets 11 in a selected area toactivate an anchoring mechanism, for example, as described herein, andmay be subsequently removed. As illustrated in FIG. 15, the outer device25 may be removed, for example, by opening the catching basket 108 insuch a manner that the outer device 25 is released and can be removedthrough the second delivery catheter 100. Alternatively, the outerdevice 25 can be cut by a separate cutting mechanism, e.g., a catheteradvanced over the outer device in place of the second delivery catheter100. The outer device could also be cut by an electric current thatleads to the heating and rupture of a selected weak point of the outerdevice. It could also be made of a resorbable material and be degradedover a certain period of time.

Although the invention has been described on the basis of embodiments,the invention is not intended to be restricted to these embodiments, butis intended to cover all modifications, equivalents and variationswithin the spirit and scope of the invention as disclosed herein. Inthis regard, for example, the described methods may be carried out onthe beating heart or on the arrested heart.

The invention claimed is:
 1. A transcatheter atrio-ventricular valveprosthesis disposable in a connection channel between atrial andventricular chambers of a heart having a circumferential connectionchannel wall structure, the transcatheter atrio-ventricular valveprosthesis comprising: an inner device having an inflow end and anoutflow end and comprising a support structure that is radiallyexpandable; a valve disposed within and attached to the inner device;and an outer device having a helical shape and configured to surroundthe inner device between the inflow end and the outflow end, the outerdevice comprising an elongate body having a first end and a second endthat is not connected to the first end, the outer device being biased toform a helix including a plurality of loops configured to receive aportion of the circumferential connection channel wall structure andclamp the portion of the circumferential connection channel wallstructure between the plurality of loops and the inner device.
 2. Theprosthesis according to claim 1, wherein the outer device is made of anelastic wire material.
 3. The prosthesis according to claim 1, whereinthe inner device is a tubular stent.
 4. The prosthesis according toclaim 3, wherein the stent is a self-expanding stent.
 5. The prosthesisaccording to claim 1, wherein the support structure comprises an outercircumferential groove formed as a radially inwardly extending recess inthe support structure.
 6. The prosthesis according to claim 5, whereinthe outer device is aligned with the groove.
 7. The prosthesis accordingto claim 6, wherein the circumferential groove, in cross-section, has awidth corresponding to a cross-sectional dimension of the elongate bodyor slightly greater than the cross-sectional dimension of the elongatebody so that the circumferential connection channel wall structure canbe clamped by the outer device against opposing lateral walls of thecircumferential groove.
 8. The prosthesis according to claim 5, whereinthe outer device is positioned within the groove.
 9. The prosthesisaccording to claim 1, wherein the inner device comprises a tubularfunnel portion that corresponds to a funnel shape of the connectionchannel.
 10. The prosthesis according to claim 9, wherein the outerdevice is configured to extend around the inner device at a positionsuch that the outer device does not overlap the funnel portion of theinner device.
 11. The prosthesis according to claim 1, wherein: thesupport structure is radially expandable to be able to exert an activeoutward radial force against an inner periphery of the circumferentialconnection channel wall structure; and/or the outer device iscontractible to be able to exert an active inward radial force againstan outer periphery of the circumferential connection channel wallstructure.
 12. The prosthesis according to claim 1, wherein the supportstructure and/or the outer device are formed from a shape-memorymaterial.
 13. The prosthesis according to claim 1, wherein the supportstructure is provided with a compressible material arranged on andaround an outer periphery of the support structure.
 14. The prosthesisaccording to claim 1, wherein: the outer device further comprises ananchor member having one or more anchor parts to penetrate into thecircumferential connection channel wall structure at a position at orclose to the elongate body; and the anchor member comprises an eyethrough which the elongate body extends to thereby by anchored on thecircumferential connection channel wall structure.
 15. The prosthesisaccording to claim 1, wherein the support structure is made of amesh-like structure.
 16. The prosthesis according to claim 1, wherein anouter surface of the support structure of the inner device is free ofprojections.
 17. The prosthesis according to claim 1, wherein: thesupport structure is radially expandable to be able to exert an activeoutward radial force against an inner periphery of the circumferentialconnection channel wall structure; the outer device is contractible tobe able to exert an active inward radial force against an outerperiphery of the circumferential connection channel wall structure; andan outer surface of the support structure of the inner device is free ofprojections.